Heat insulation for building structures, used in attics, walls, floors, etc., typically comprises loose material that can be blown into place, particularly into attics, or blanket material that can be manually placed between parallel studs, joists, etc. Generally, the insulation material forms a network of air pockets or gaps which retard the transfer of heat by convection and conduction. The blanket material can comprise fiberglass, cellulose, mineral wool, and other particulate material that traps a multitude of air gaps or spaces between the fibers or other discrete items in the blanket.
In addition to using the fiber sheet insulation material for convection and conduction insulation, it is also possible to use a heat reflective material to function as a radian heat barrier. The radiant heat barrier can be used alone or in combination with the conduction and convection heat insulation. The radiant heat barrier can comprise a sheet of foil that has heat reflective surfaces on one or both sides. The foil sheet can be attached to convection and conduction heat insulation material for providing added radiant energy with reflective properties, thus adding to the total insulating value of the insulation assembly. Typically, the assembly would be placed between parallel joists, studs, etc of an outside wall of a building structure. However, it has been found that when the reflective foil sheet makes contact with adjacent surfaces, the foil loses its heat reflective properties in the area where contacted.
Because of this characteristic, the tendency for providing a heat reflective insulation sheet is to arrange the sheet so it contacts as few as possible adjacent surfaces. For example, my U.S. Pat. No. 5,918,436 discloses an insulating finishing material having multiple sheets of foil of different areas attached together at the edges so that when suspended between parallel joist, etc., the lower sheet sags due to gravity a distance away from the upper sheet, creating an air gap between the sheets. This air gap functions as insulation from convection and conduction heat transfer, but also protects the internal radiant barrier provided by the foil from contact with other objects, thereby maintaining its heat reflective properties. Additionally, the enclosed space formed by the two overlying sheets usually prevents the invasion of dust, stray fibers, grit, sawdust, and other materials that might otherwise make contact with the reflective surface and reduce the reflective capability of the surfaces.
While the radiant barrier concept as disclosed in my U.S. Pat. No. 5,918,436 is effective to this end, it is highly desirable to have the insulation structure in elongated configuration that will be able to span across adjacent purlins or across adjacent rafters or other objects in the roof structure, and assume an inflated configuration on opposite sides of such objects. This inflation of the radiant barrier insulation on opposite sides of the purlins, etc. on which the radiant barrier rests creates the desired air gap between the radiant reflective surface and the facing material. This preserves the reflective capability of the radiant material. It is to this improvement that this invention is focused.